Here’s a quick tip regarding reference lines and forms in the conceptual mass interface:

When a form is created the original lines will be deleted when you delete the form. If you created the form with reference lines however they do remain when the form is deleted. This tip was posted a while back in this post.

But let’s say you created a form with lines and you need to both delete the form and maintain the original lines.

You can trace the original form with reference lines, or pick points with reference lines. Also you can enable 3D Snapping to trace any points on the form if you needed a particular portion of it.

If snapping to 3D points to create reference lines, you will need to cut the points to the clipboard prior to deleting the form. After the form is deleted you can paste > same place and create a new form as needed from the reference lines.

Here’s a quick video [no sound] displaying an example of these 2 options:

Video Example

Hope this helps!